It is well known that CO.sub.2 lasers conventionally produce output in the 9.6 and 10.6 .mu.m range. However it has been a problem to obtain an output from any laser in the 16 .mu.m range. A CO.sub.2 laser capable of producing at least a fraction of a joule/.mu.sec in the 16 .mu.m range is desirable for the purposes of producing isotope separation in uranium. This invention opens an entire field of new, high power lasers utilizing different molecular gases.